Telegraph printing system



Jan. 13, 1942. J SPENCER 2,269,559

TELEGRAPH PRINTING SYSTEM Filed May 16, 1959 4 Sheets-Sheet 1 V INVENTOR. 40755 )4. J'PENJE? ATTORNEY.

Jan. 13, 1942. J SPENCER 2,269,559

TELEGRAPH PRINTING SYSTEM Filed May f6, 1959 4 Sheets-Sheet 2 Fig.2

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TELEGRAPH PRINTING SYS TEM Filed May 16, 1939 4 Sheets-Sheet 3 INVENTOR- Jfl/flff 19. JAE/V65? BY 7% z I ATTORNEY.

Jan. 13, 1942. J. A. SPENCER TELEGRAPH PRINTING SYSTEM Filed May 16, 1939 4 Sheets-Sheet 4 1 M 5 hkwfl INVENTOR. $4075. 9 4. J'PfA/Cfi? ATTORNEY Patented Jan. 13, 1942 ass:

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TELEGRAPH PRINTING SYSTEM James A. Spencer, Teaneck, N. J., assignor to Radio Corporation of America, a corporation of Delaware 19 Claims.

This invention relates to mechanism for use in radio and wire telegraph systems. In multiplex telegraphy using equal length code characters a plurality of channels, each having its own-tape transmitter at the sending station and printing mechanism at the receiving station, are successively assigned to a radio or Wire link for the duration of one code group. This enables one to utilize all the time allotted to each channel for the sending of the messages, while the local printing functions, such as setting up the tape combinations and operating the printer, are taken care of for one channel while another channel is sending on its allotted time. In prior art, simplex telegraphy for equal length code characters, however, the whole time is not utilized in transmission of the character code signals. Therefore the connecting radio or wire link is kept idle while the local functions are being performed. In my copending application filed January 21, 1939, Serial No. 252,179, I disclosed a sending and receiving mechanism that remedies this difiiculty but a large number of electromagnets and associated contacts are provided for storing thesignals while local functions are being performed.

Itis an object of this invention to provide a simple system with a minimum number of electromagnets for utilizing all the circuit time for transmission of signals having equal length code characters and to perform the local operations while another combination is being transmitted.

Another object is to provide a simplified system with aminimum number of electromagnets in single channel telegraphy, employing equal length code characters in which all the circuit time is used for transmission of the message.

Another object is to provide a simple single channel system using equal length code characters by storing a part of a code unit in a sending=or= receiving device for suflicient time to permit the performing of its local operations.

Otherobjects will appear in the following description, reference being had to the drawings in which:

Fig. l. is a circuit diagram of the apparatus at the sending station.

Fig. 2 is a section of a perforated tape giving the perforations for the letters of the alphabet in a seven unit equal length code.

Fig. 3 is a graph of the potential or current of a signal'message.

Fig. 4.15 a circuit diagram of the receiving system.

Fig. 51is an illustration of the battcry connecmechanism.

tions for operation of the sending and receiving mechanism.

Fig. Sis a diagrammatic illustration of a portion of a telegraph printer.

Fig. 7 is an illustration of part of the printing Referring to Fig. 1, T indicates generally the tape transmitter such as the Benjamin, or other type, which in this .case has seven seeker pins resiliently urged byoperating'magnet 2 against a perforated tape which holds the seeker pin from further movement if no hole has been punched therein but if a hole is present for any particularxseekerit engages its contact. There are seven of these contacts numbered I to l in the drawings. The perforated tape and the mechanism for movingthe tape forward and raising the seeker pins thereagainst have not been illustratedbecause they are old and well known in the art.

tacts 17, I8 and 19, connected to the positive I terminal. Switch tongues 20, 2! and 22 making and breaking these contacts are connected respectively to segments sl to $3 of the distributor generally indicated at 23. This distributor is run at a speed that is maintained constant by well known mechanism which is not' illustrated,

" but reference is made to patents to Callahan,

Mathes, and Kahn, No. 2,010,505, and the patent to Mathes, No. 2,038,375, for a detailed description of such devices. Brushes and short-circuiting' bar 2 3 connect these segments successively to collector ring 25 and to outgoing line 21 of the. radio or wire'link asthe case may be.

Armatures 28, 29, 30 and 3| which act as catches or supports for levers32, 33, 34 and 35, cannot be moved by selector magnets S4, S5, S8 and S1, respectively, except when they are unlocked by their respective levers. These levers are diagrammatically illustrated as being all connected together for operation by armature 36 when magnet 31 is energized. This magnet 37 is electrically connected to switch tongue 38 normally held out of engagement with positive contact 39 by levers 4| when held in position by armature 42. This armature is operated by magnet 43 which is connected to segment s'l of the distributor 23. The segments's'l to s'! are part of the distributor 23 and are successively connected by brush 44 to collector ring 45 which is connected to the positive terminal 46.

Reset magnet 41 is connected to switch tongue 48 of relay 49. This relay has operating coil 53 connected between ground and segment s'fi. This magnet has a spring controlled armature which holds lever 52 in position to prevent tongue 48 from engaging contact 53. Reset magnet 41 operates bell crank 54 and through its arm 55 moves lever H back to reset condition with switch tongue 20 in engagement with contact I4. When the magnet is deenergized and the lever has been reset spring 56 moves the armature back under the lever H to hold it in position. Levers I2, 13 and 52 are similarly resiliently actuated and are reset by arms 51, 58 and 59 which are connected to bell crank 54 by shaft 60 so that they rotate in unison with arm 55. Reset magnet 31 moves the arms 32, 33, 34, 35 and GI and unlocks the armatures or catches 28, 29, 30 and 3| engaging the levers 62, 63, 64 and 65. These levers in locked positions close the upper contacts and in the unlocked position open them and close the lower contacts. The arms 32 to 35 and BI, also reset the lever arms 62 to 65 and 4|, and permit the springs to pull the armatures back into engagement with the respective lever arms when the magnets are deenergized.

In Fig. 4 the receiving apparatus is shown and it is identical with the apparatus of Fig. 1 with certain exceptions that will be referred to later. In view of the similarity of the construction and operation the reference characters in Fig. 4 have in general been given the same reference character as similar parts in Fig. 1 with the distinguishing letter 1' added thereto. In View of this a complete description of Fig. 2 is unnecessary since the description of Fig. 1 will enable one to understand Fig. 2.

The differences between Fig. 4 and Fig. 1 previously referred to are chiefly as follows:

The segments srl to sr1 of the distributor 231', which is run synchronously with distributor 23, areconnected to selector magnets Srl to S11 respectively. The printing magnet 13 is connected to switch tongue 391 in parallel with reset magnet 31r. Magnet 431* is connected to distributor sr1 and the selector magnet 50 is connected to the third local segment sr3.

The operation of the transmitter will now be described with the assumption that the word hand is being transmitted as a word in the message. It will be assumed that brushes 24 and 44 have just made engagement with segments s4 and s4 respectively, as all code combinations start at this time. This energizes tape transmitter magnet 2 and moves the tape so that the perforations for the letter H are in position over the seeker pins (see Fig. 2). Contacts 2, 5 and 6 are then engaged by their seeker pins while the other contacts are held from engagement with their seeker pins due to the absence of perforations. Magnets S2, S5 and S6 are immediately energized. The armature of magnet S2 moves and switch lever I2 drops, closing mark contact l8 and opening space contact i5. The armatures of magnets S4 and S5 cannot move at this time, as they are locked in the notches of their switch levers. Disregarding the previous signal that is being completed and referring only to the code signals for the letter H, it may be said that nothing happens when the brushes engage segments s5, s5, as the armature of selector magnet S5 is locked in position but the magnet remains energized.

When segment s6 is engaged no current flows thereto but at this time the engagement of brush 44 with segment 8'6 energized magnet 59. This at once energizes reset magnet 41 and at about the same time brush 44 leaves segment s'6 and deenergizes magnet 53. Reset magnet 41 moved the levers 55, 51 and 58 back into raised position and all catches except 9, were moved by their springs into position to support the levers if they had been lowered on receipt of the previous signal. Catch 9 was not moved because magnet S2 is energized.

When segments s1 and s1 are engaged nothing happens as far as the letter H is concerned. When segment s! is engaged a negative pulse 14 (Fig. 3) is sent from the negative line through upper contact 14 segment sl to ring 25 and to the radio or wire link 21. This is the beginning of the transmission of the letter H. Prior to this time, namely, while the brush was moving over segments 4, 5, 6 and 1, the code signal was stored. Also at this time magnet 43 is momentarily energized and catch 42 moved from under lever 4| and tongue 38 engages contact 39. This ener' gizes reset magnet 31, which raises levers 62, 63, 64, 65 and M. This permits energized magnets S5 and S6 to attract their armatures. At about this time brush 44 leaves segment 8'! and relay 43 and magnet 31 are de-energized. The deenergization of magnet 31 drops levers 34 to 35 inclusive and 61, which leaves levers 62 and 65 in space position (negative current), as magnets S4 and S1 are not energized. Levers 63 and 64, however, drop to mark position (positive current) as armatures 29 and 30 are held out of the notches in such levers by the energization of magnets S5 and Se.

When the brushes engage segment s2 a positive pulse 15 (Fig. 3) is sent over the line 21 as selector magnet S2 is still energized and tongue 2| is in engagement with positive contact [8. Engagement of brush 44 with segment s'2 does not produce any result as it is a blank segment. Upon brush 24 engagement segment 33 negative pulse 16 is sent over line 21 since selector magnet S3 is not energized and the negative contact is in engagement with tongue 22. Segment s3 is a blank and no current is passed when brush 44 engages it.

Engagement of brush 24 with segment s4 sends out negative pulse 11 as selector magnet S4 is not energized. Simultaneously brush 44 engages segment s4 and tape transmitter magnet 2' is operated which retracts the seeker pins, moves the tape to position for the next letter A and raises the seeker pins, but only pins I, 3 and 4 engage their contacts. (See Fig. 2.) This energizes selector magnets SI, S3 and S4, and deenergizes selector magnets S2, S5 and S6, for the previous letter H. The signal pulse for selector magnet S2 has already been transmitted so deenergization of magnet S2 cannot aifect the transmission of the letter H. Also, the transmission of the letter H will not be affected by deenergization of selector magnets S5 and S6 because the levers 63 and 64 are in lowered position with the catches outside the locking notch.

When brush 24 engages segment s5 positive pulse 18 is sent to line 21 as the tongue of selector sl is in engagement with the positive contact. Nothing happens when brush 44 engages segment s5 except that tape Operating magnet 2' would be energized if such magnet did not complete its operation by engagement of the brush with segment. s l. This double connection is not absolutely necessary but since segment s5 is otherwise a vacant'one it is joined to 3'4 to assure that the magnet will always operate. Upon brush 24 engaging segment s5 positive pulse I9 is sent over the link ZI-because selector lever 64'is in lowered position with catch 3!! locked against movement by its spring. Also at this time reset magnet 4! is operated by engagement of brush 44 with segment s1 5 which energizes relay coil 50. This stores the first and third code unit of the letter A by keeping selector magnets sI and s3 energized with levers Z and 22 reset for the next code combinations of the message. As the brush 24 reaches 81 negative pulse 80 is transmitted over line 2! because was not energized for the code combination in the letter H. The letter H has now been fully transmitted and the combination for the next letter A has been set up.

When brush 24 engages segment sI positive pulse 8I of the combination for the letter A is transmitted and magnet 43 is energized by brush 44 engaging segment sI. This moves armature 42 and permits arm 4| to drop and close contacts 38, 39, which energizes magnet 31 and causes levers 62 to 55 and II to be raised. Lever 28 will not be held by its catch and it is moved by magnet S 5 which is energized. This permits lever 62 to drop to positive current position when magnet 3! is de-energized and the armature lever 28 is locked in attracted position, but levers 63, 64 and 65 are held in negative current position by the armatures of de-energized magnets S5, S6 and S7. As the brushes continue to rotate the. transmission of the letter A will be completed by negative pulse 82, positive pulses 83 and 84 and negative pulses B5 and 86. A new combination is set up on the tape transmitter when segment s4 is reached. I

The letter N will be similarly transmitted by negative pulse 81, positive pulses 88 and 89 and negative pulse 99, positive pulse 9i and negative pulses 92 and 93. When segment 5' was reached the combination for the letter D was set up and on the next rotation of the brushes positive pulse 94, negative pulses 95, 9%, positive pulses 91, '98, and negative pulses 99 and IIlIl will be transmitted.

It will be seen that the transmission of the message is delayed one revolution of the brushes by storing the code units.

This momentary delay is of course not noticeable insofar as the speed of transmission of the message is concerned, but it gives ample time to perform the local function of setting up the tap transmitter for a code combination,

It will be apparent that one or more code units can be successively repeated without in any way changing the method of operation above described.

I have shown a circuit arrangement in Fig. 8 for converting positive and negative pulses at the receiver into on and off signals through polar relay IIII connected to incoming line I32. Obviously this would be omitted if this conversion were accomplished at some other point in the radio or wire link. The operation of the receiving apparatus is quite similar to that of the transmitting apparatus except the printer itself. The method of operation is as follows:

Referring to Figs. 4 and 6 and assuming that the: first negative pulse M of the transmitted letter H, or other pulse formed therefrom, has arrived at the polarized relay It I, the switch tongue of the relay. will be moved against dead. contact I03 and no current will flow when brush 241 engages segment srI of distriubutor 237'. Also, no current will flow from segment s'rI at this time. a

When positive pulse I5 arrives at relay IOI the relay tongue will be moved against the positive contact I04. At this time brushes 2dr and 441' will be on segments $12 and sr2 and relay STZ will be energized. The energization of this relay closes the circuit to selector magnet 67 of the printerv through contact I81 (see also Fig. 6'). In the printer shown in Fig. 6 the latch and selector mechanism for relay 65 is the only one completely illustrated but the other relays have exactly similar parts.

When magnet 61 was energizedit attracted one end of its armature I95 (note illustration for magnet 66) pivoted in the center, against the tension of its returning spring and projected the opposite end into notch I06 of selector bar Iill, there being a selector bar for each selector relay. The armature is held in this position by latch I08 so that when the brush 241' leaves segment $12 of the commutator the armature will remain in its operated position. The selector magnets 66 to I2 and their armatures I05 and latches I08 are all secured to the movable carriage I09.

When negative pulse I6 arrives the switch tongue of polarized relay IBI will be thrown against the dead contact IE3 and printer magnet 68 will not be energized. At this time segment 5T3 causes the operation of reset magnet Mr, resetting levers IIr, I21, I31" and 521*, so they will be ready for the next code character. Negative pulse 11 like allnegative pulses will not cause a selector magnet to be operated.

When positive pulse I8 arrives relay IIJI will energize magnet Ii! as brush Mr isin engagement with segment 8'75. When brush 241 engages seg-. ment srB pulse I9 causes magnet II to be energized. As in the case of magnet 61, magnets II! and H operated their armatures and projected their ends into notches (indicated only for magnet 68) in selector bars Band III fragmentarily shown in Fig. 6. All selector bars are broken away but each bar has a properly positioned notch such as, notch I22 more particularly referred to later herein.

When magnets 61; Ill and II operated their armatures each of them also closed contacts through a cut-out shaft and lever, diagrammatically illustrated as simple switch contacts II3. arranged in parallel, each in Fig. 6, closing a circuit to relayl3 but as shown in Fig. 4, the cir cult is open at contact 391" of relay em, connected to segment s'rl on commutator 441'. Therefore, when brush 44 engages this segment relay 431' is energized which closes contacts 391 and energizes, magnet 311" causing it to reset levers 62r to 651' and also lever Mr, clearing the selector relaysrsm to srI for the next signal unit. Relay 431" also energizes relay magnet '73 which closes switch contacts I I I and energizes operating magnet. I I5. Armature I I6 then moves the printed carriage II! (the middle portion being shown broken away) towards the left by means of plunger H8.

Sincethe seven selector magnets 56 to 12 and their respective armatures are mounted on carriage II! the selector bars Illl, I I6 and III are moved with the carriage because the projecting ends ofarmatures I05 of selector magnets 6|, Ill and II engage the edges of notches identical with I06. The remaining selector bars are not moved with the carriage. Shortly before the motion to the left is completed trip II9 engages latch I08 and permits the armatures similar to I05 to spring back into place. The armatures are freed from friction against the ends of notch I06 at this time by leaf spring I20 entering notch I2I in the three selector bars which snaps the selector bars slightly to the left. Selector magnets 61, I and II then resume their normal condition. When the three selector bars reach their extreme left-hand position notches I22 in the three selector bars corresponding to the letter H are in alignment, there being also notches in the other bars in alignment with notch I22 at this point. Pull bar I23 shown more in detail in Fig. 7, is then in position to drop into these aligned notches but it is held from this movement by the printing bail I24 engaging hump I25 on the pull bar.

When the carriage reaches its extreme movement to the left it opens switch contacts I26 and breaks the continuity of the holding circuit of relay "I3. This deenergizes the relay and opens the contacts I I4 which in turn deenergizes carriage magnet I I5. The carriage return spring I2'I thereupon returns the carriage to the right against stop I28.

As the selector bars I01, H0 and III moved to the left in the initial motion of the carriage they engaged return lever I20 and turned it around its center point against the tension of its spring I30. Latch I3I immediately snapped into position and held the return lever so that the selector bars were not returned to the right at that time.

As the return lever I29 snapped into the notch of latch I3I printing contacts I32 closed and printing relay I33 was energized. This closed contacts I34 and energized printing solenoid I 35. This solenoid pulls the armature I36 downwards with its extension I31 which is pivoted to printing bail I24, the bail being pivoted at an intermediate point I38. This moves the bail upwards (Fig. 7) and permits the pull bar I23 to drop into the aligned notches I22 in the selector bars. As it does this the upwardly moving projection I39 engages the hump I25 in the pull bar and moves it upwards with the bail. This throws the type bar I4I downwards and strikes the type-pallet against the ribbon on platen I42. This prints the letter H.

Just at the time that the armature I36 of the printing solenoid completed its movement projection I43 engaged the latch I3I and permitted the return lever I29 to return the three selector bars to the right whereupon leaf spring I20 snapped into groove I44 which holds these three bars together with the others in their initial position. At about this time projection I45 opens switch contacts I46 and deenergizes the printing relay and the printing solenoid magnet. The plunger is then returned to its initial position by spring I41 (Fig. '7). This returns the pull bar and brings the printing bail I24 against the hump I25 of the pull bar and moves it outward clear of the selector bars.

The selected letter H has thus been printed and all mechanism of the printer has returned to the original position. However, the selection of the next transmitted letter was not held up pending the operating of the printing mechanism. Since the relay sr2 was reset when segment sr3 was engaged by brush Mr and relays sr and s16 were reset when segment s'rI was similarly engaged, those relays were available for the subsequent signal unit. The selector magnets assumed their inoperated position before the printer magnet was energized so signals can be stored in the printer as soon as the brush 241' reaches the corresponding commutator segments. In view of this the printing mechanism has substantially one full revolution of the commutator for completion of the printing operation itself. During this printing operation the signal code reception continues without interruption as the impulses, in effect, are stored while the printing is completed.

The letters AND will be printed similarly to the letter H and the operation need not be further described.

Since the printing system of my invention operates independently of the tape transmitters and printers of other channels its greatest advantage over prior art systems is in single channel printing operations.

The transmission system of Fig. 1 can be used with the receiver of my above mentioned application and the receiver of this application can also be used with the transmitter of such application. Also other receivers could be designed for working with the transmitter of this case and other transmitters could be designed for working with the receiver disclosed herein. Therefore, the transmitters and receivers are not limited to any one cooperating system.

The invention has been disclosed in connection with a seven-unit code group, but it is not limited thereto. It may be used with other code groups of a difierent number of units; for example, the five-unit code group.

I have illustrated circuit arrangements that have been found satisfactory but the invention is not to be limited thereto as various changes could be made without departing from the spirit of the invention.

Having described my invention, what I claim 1. In a transmitter for multiunit code characters, a tape transmitter for sending the signal units to indicate a message, an outgoing line, a switch for each code unit, means for connecting the switches in succession to said line, a magnet for each code unit each having an armature for positioning one of said switches in a signal position, means for energizing the magnets for a new character in the middle of the transmission of the previous character and means for locking the armatures of the magnets for the untransmitted units of said previous character until their associated switches have been connected to the outgoing line.

2. In a transmitter for multiunit code characters, a tape transmitter for sending the signal units to indicate a message, an outgoing line, a switch for each code unit, means for connecting the switches in succession to said line, a magnet for each code unit each having an armature for positioning one of said switches in a signal position, the coils of said magnets being connected to the tape transmitter, means for moving the tape for energization of the magnets for a new character before the signal units have been transmitted for the previous tape setting and means for locking the armatures of the magnets for the remaining units until their associated switches have been connected to the outgoing line.

3. In a transmitter for multiunit code characters, an outgoing line,la switch for each code unit, means for connecting the switches in suc-,

cession to said line, amagnet for each code unit each having-an armature for positioning one of said switches in one signal position, means for energizing the magnetsin accordance with the characters to be transmitted, a restoring magnet having an armature for moving the switches from said position to another signal position after the time for a predetermined number of signal units for each code group has passed, and a second restoring magnet having an armature for moving the remaining switches from said position to the other position after the time for all the signal units of such code group has passed.

4. In a transmitter for multiunit code characters, a tape transmitter for sending the signal units to indicate amessage, an outgoing line, a

switch for each code unit, means for connecting the switches in succession to said line, a magnet for each code unit each having an armature for moving one of said switches to one signal position, the coils of said magnets being connected to the tape transmitter for energization thereby, a restoring magnet having an armature for moving the switches from said position to another signal position after the time for a predetermined number of signal units for each code group has passed, and a second restoring magnet having an armature for moving the remaining switches from said position to the other position after the time for all the signal units of such code group has passed.

5. In a receiving system for multiunit code characters, a conductor for receiving the incoming signal units, a printer having a selector magnet for each code unit, a selector switch in the circuit of the coil of each selector magnet, a relay for each signal unit each having an armature for operating one of said selector switches as its signal unit is received over said conductor, a restoring magnet having an armature for moving operated selector switches to unoperated position after the time for a predetermined number of signal units for a code group has passed and a second restoring magnet having an armature for moving the remaining operated selector switches to their unoperated position before the signal units of the next code group have been received.

6. In a receiving system for multiunit equal length code characters, a conductor for receiving the incoming signal units, a printer having a selector magnet for each code unit, a selector switch in the circuit of the coil of each selector magnet, a relay for each signal unit each having an armature for operating one of said selector switches as its signal unit is received over said conductor, a restoring magnet having an armature for moving operated selector switches to unoperated position after the time for a predetermined number of signal units for a code group has passed and a second restoring magnet having an armature for moving the remaining operated selector switches to unoperated position after the time for all the signal units of such code group has passed.

7. In a receiving system for multiunit equal length code characters, a conductor for receiving the incoming signal units, a printer having a selector magnet for each code unit, a selector switch in the circuit of the coil of each selector magnet, a relay for each signal unit each having an armature operating one of said selector switches as its signal unit is received over said conductor, a restoringmagnet having an armature for moving operated selector switches to unoperated position, a restoring relay for energizing the restoring magnet after the time for a predetermined number of signal units for a code group haspassed, a second restoring magnet having an armature for moving the remaining operated selector switches to unoperated position and a second restoring relay for energizing the second restoring magnet after the time for all the'signal units of such code group has passed.

8. In a receiving system for multiunit equal length code characters, a conductor for receiving the incoming signal units, a printer having a selector magnet for each code unit, a selector switch in the circuit of the coil of each selector magnet, a relay for each signal unit each having an armature operating a selector switch to closed position as its signal unitis received over said conductor, a restoring'magnet having an armature for moving operated selector switches to unoperated position, a restoring relay for energizing the restoring magnet after the time for a predetermined number of signal units for a code group has passed, a second restoring magnet having an armature for moving the remaining operated selector switches to unoperated position and a second restoring relay for energizing the second restoring magnet after the time for all the signal unitsof such code group has passed, each of said restoring magnets having means for restoring its energizing relay.

9. In an electric telegraph system for multiunit equal-length code characters, two groups of relays, a movable switch lever for each relay, means controlled by the armatures of said relays for positioning the switch levers in one position, means for simultaneously energizing a predetermined number of said relays for each code character of a message, means whereby the armatures of the energized relays of one group cause the first means to position the switch levers in another position, means connected with the first means for locking the armatures of the other group of relays from movement and means for moving the switch levers of the second group of relays from the second-mentioned position to the first-mentioned position and for causing the third means to release the armatures.

10. In an electric telegraph system for multiunit equal-length code characters, two groups of 'relays, a movable switch lever for each relay biased to engage a contact of one potential, means controlled bythe armatures of said relays-for positioning the'switch levers to engage a contact of another potential and for releasing them for engagement with the contact of the first potential, means for simultaneously energizing a predetermined number of said relays for each code character of a message, means whereby each energized relay of one group immediately moves its armature and the'switch lever moves into engagement with the contact of the first potential, means connected with the first means for locking the armatures of the other group from movement and means for moving the switch levers of the second group from engagement with the contact of the first potential to engage the contact of the second potential and for moving the locking means to release the armatures.

11. In an electric telegraph system for multiunit equal-length code characters, two groups of relays, a movable switch lever for each relay biased to a first position, arms engaging the armatures of the relays'for supporting the switch levers in a second positionand for releasing them for movement to the first position, means for simultaneously energizing a predetermined number of said relays for each code character of a message, means whereby each energized relay of one group immediately moves its armature from engagement with the first means and its switch lever moves to said first position, lugs on the arms associated with the armatures of the other group for locking their associated armatures from movement and means for moving the switch levers of the second group from said first position to the second position and substantially simultaneously moving the arms of said second group to unlock their engaging armatures.

12. In an electric telegraph system for multiunit equal-length code characters, two groups of relays, a movable switch lever for each relay biased to a first position, means engaging the armatures of the relays for supporting the switch levers in a second position and for releasing them for movement to the first position, means for simultaneously energizing a predetermined number of said relays for each code character of a message, means whereby each energized relay of one group immediately moves its armature from engagement with the first-mentioned means and its switch lever moves to said first position, means connected with the first-mentioned means for locking the armatures of the other group from movement, means for moving the switch levers of the first group from said first position to the second position, and means for moving the switch levers of the second group from said first position to the second position and substantially simultaneously moving said locking means to release their engaging armatures.

13. In an electric telegraph system for multiunit equal-length code characters, an outgoing channel, a first and second group of relays, a movable switch lever for each relay biased to a first position, means engaging the armatures of the relays for supporting the switch levers in a second position and for releasing them for movement to the first position, means for electrically connecting the switch levers in succession to said channel, means operated after the connection of the last switch lever of the first group to said channel for simultaneously energizing a predetermined number of said relays for each code character of a message, means whereby each first means for holding the armatures of the second group from movement and means for moving the switch, levers of the second group of relays from said first position to the second position and substantially imultaneously moving said locking means to release the armatures.

14. In an electric telegraph system for multiunit equal-length code characters, an outgoing channel, a first and a second group of relays, a movable switch lever for each relay biased to mark position, means engaging the armatures of the relays for supporting the switch levers in space position and for releasing them for movement to mark position, means for electrically connecting the switch levers in succession to said channel, means operated after the connection of the last switch lever of the first group of relays to said channel for simultaneously energizing a predetermined number of said relays for each code character of a message, means whereby each energized relay of the first group immediately moves its armature from engagement with the first means and its switch lever moves to mark position, means connected with the first means for locking the armatures of the relays of the second group from movement means for moving the switch levers of the second group of relays from mark position to space position and for moving the locking means to release the armatures, and means for causing the last-mentioned means to operate after the connection of the last switch lever of the first group to said channel.

15. In an electric telegraph system for multiunit equal-length code characters, an incoming channel, two groups of relays, a movable switch lever for each relay, means controlled by the armatures of said relays for positioning the switch levers in one position, means for electrically connecting the coils of said relays in succession to said channel, means whereby the armatures of the energized relays of one group causes the first means to position the levers in the first position, means connected with the first means for locking the armatures of the other group of relays from movement, a printer having selector bars, an operating magnet, a printer selector magnet electrically connected to each of said switch levers and having means when energized to connect a selector bar to the operating magnet for movement thereby, means for moving the switch levers oi the second group of relays from the second position to the first position and for moving said locking means to release the armatures and means for energizing said operating magnet after connection of the last relay of the second group to said channel.

16. In an electric telegraph system for multiunit equal-length code characters, an incoming channel, relays arranged in a first and a second group, a movable switch lever for each relay biased to a first position, means controlled by the armatures of said relays for positioning the switch levers in a second position, means for electrically connecting the coils of said relays in succession to said channel, means whereby the armatures of the energized relays of the first group move and the first means positions the levers in a second position, means connected with the first means for locking the armatures of the second group of relays from movement, a printer having selector bars, an operating magnet, a printer selector magnet electrically connected to each of said switch levers and having means when energized to connect a selector bar to the operating magnet for movement thereby, means for moving the switch levers of the second group of relays from the first position to the second position and for moving said locking means to release the armatures after the connection of the coil of the last relay of the second group to said channel and means for energizing said operating magnet after said connection of the last relay of the second group to said channel.

17. In an electric telegraph system for multiunit equal-length code characters, an incoming channel, relays arranged in a first and a second group, a movable switch lever for each relay biased to mark position, means engaging the armatures of the relays for supporting the switch levers in space position and for releasing them for movement to mark position, means for electrically connecting the coils of said relays in succession to said channel, means whereby each energized relay of the first group immediately moves its armature from engagement with the first means and its lever moves to mark position,

of the third relay of the second group to said channel for moving any unsupported switch lever of the first group from mark position to space position, means connected with the first means for locking the armatures of the second group of relays from movement, a printer having selector bars, an operating magnet, a printer selector magnet electrically connected to each of saidswitch levers and having means when energized to connect a selector bar to the operating magnet for movement thereby and means for moving the switch levers of the second group of relays from mark position to space position and substantially simultaneously moving the locking means to release the armatures after the connection of the coil of the last relay of the second group to said channel, and means for energizing said operating magnet after said connection has been made.

18. In a receiving system for multi-unit code characters, a conductor for receiving the incoming signal units, a printer having a selector magnet for each code unit, a selector switch in the circuit of the coil of each selector magnet, a relay for each signal unit, means whereby the armature of each relay moves one of said selector means operated after the connection of the coil switches to one position as its signal unit is received over said conductor, means for moving the operated selector switches to unoperated position after the time for a predetermined number of El] signal units for a code group has passed and means for moving the remaining operated selector switches to their unoperated position before the signal units of the next character have been received.

19. In a receiving system for multi-unit equallength code characters, a conductor for receiving the incoming signal units, a printer having a selector magnet for each code unit, a selector switch in the circuit of the coil of each selector 5 magnet, a relay for eachv signal unit, means 20 tion after the time for the reception of a predetermined number of signal units for a code group has passed and means for moving the remaining closed selector switches to open position after the time for the reception of all the signal units 25 of such code group has passed.

JAMES A. SPENCER. 

